1.1 本试验方法包括测定粘度范围为1.70 毫米 2. /s至6.20 毫米 2. /40时的s（cSt） °C。 注1: 本试验方法范围内的ASTM规范燃料为规范 第396页 2级，规范 1975年 等级2-D和规范 880年 2-GT级。 注2: 该试验方法已用于较低粘度的中间馏分燃料，如规范 第396页 1级，规范 1975年 1-D级和规范 880年 1-GT级，但尚未研究精度，因此未验证这些等级的规定精度。 1.2 本试验方法不适用于含有未溶解水的燃料。 1.3 以国际单位制表示的值应视为标准值。 1.3.1 包括非SI单位，特别是美国常用单位，如温度（华氏度）和压力（磅/平方英寸表压（psig）），以供参考。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 本试验方法适用于实验室或现场评估馏出燃料清洁度。 5.2 储存、预处理或混合后过滤性能的变化可指示燃料状况的变化。 5.3 燃料的相对可过滤性可能因过滤器孔隙度和结构而异，并且可能并不总是与本试验方法的结果相关。 5.4 工业/炼油厂过滤器过滤性差的原因包括燃料降解产物、储存或运输过程中收集的污染物、混合燃料的不相容性或燃料与过滤介质的相互作用。其中任何一种都可能与节流孔或过滤器系统堵塞有关，或两者兼有。

1.1 This test method covers a procedure for determining the filterability of distillate fuel oils within the viscosity range from 1.70 mm 2 /s to 6.20 mm 2 /s (cSt) at 40 °C. Note 1: ASTM specification fuels falling within the scope of this test method are Specification D396 Grade No. 2, Specification D975 Grade No. 2-D, and Specification D2880 Grade No. 2-GT. Note 2: The test method has been used with lower viscosity middle distillate fuels such as Specification D396 Grade No. 1, Specification D975 Grade No. 1-D, and Specification D2880 Grade No. 1-GT, but the precision has not been studied and therefore the stated precision has not been validated for these grades. 1.2 This test method is not applicable to fuels that contain undissolved water. 1.3 The values stated in SI units are to be regarded as standard. 1.3.1 Non-SI units, specifically U.S. customary units such as temperature in degrees Fahrenheit and pressure in pounds per square inch gauge (psig), are included for information. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This test method is intended for use in the laboratory or field in evaluating distillate fuel cleanliness. 5.2 A change in filtration performance after storage, pretreatment, or commingling can be indicative of changes in fuel condition. 5.3 Relative filterability of fuels may vary depending on filter porosity and structure and may not always correlate with results from this test method. 5.4 Causes of poor filterability in industrial/refinery filters include fuel degradation products, contaminants picked up during storage or transfer, incompatibility of commingled fuels, or interaction of the fuel with the filter media. Any of these could correlate with orifice or filter system plugging, or both.